City upon a Hill is the phrase often used to refer to John Winthrop's famous sermon, "A Model of Christian Charity," based on Matthew 5:14 ("You are the light of the world. A city set on a hill cannot be hid."), in which he urged that the Puritan colonists of New England who were to found the Massachusetts Bay Colony make their new community into a "city on a hill," an example to the Christian world. It was long believed that the speech was given aboard ship not long before landing; recent research has shown, however, that it was almost certainly given in England prior to departure. In any case, it inspired the Puritans with a sense of holy duty that would be crucial if they wanted to increase their chances of survival in the New World.

Winthrop believed that all nations had a covenant with God, and that because England had violated its religious covenant, the Puritans must leave the country. This was an expression of the Puritan belief that the Anglican Church had fallen from grace by accepting Catholic rituals. Winthrop claimed that the Puritans forge a new, special agreement with God, like that between God and the people of Israel. However, unlike the Separatists (such as the Pilgrims), the Puritans remained nominally a part of the Anglican church in hopes that it could be purified from within. Winthrop believed that by purifying Christianity in the New World, his followers would serve as an example to the Old World for building a model Protestant community.

The idea that their community was specially ordained by God had a powerful effect on the Puritan society of New England. Of course, breaking a covenant with God has dire results (as Noah's fellow men learned the hard way) - as Winthrop put it, "if wee shall deale falsely with our god in this worke wee have undertaken and soe cause him to withdrawe his present help from us, wee shall be made a story and a byword through the world, wee shall open the mouthes of enemies to speake evill of the wayes of god and all professours for Gods sake." In order to avoid incurring God's wrath by breaking their promise, the Puritans sought to maintain perfect order in their society. Even the smallest sins were punished harshly by the courts; no one was allowed to live alone for fear that they would succumb to the temptation to sin; parents were to instruct their children and servants diligently in the Word of God; church attendance was mandatory; marriage was required. These conventions and institutions molded an extremely stable and well-structured society in New England, a stark contrast with the unstable and loosely-bound society of the early British colonies in the Chesapeake Bay region, such as Jamestown. These Puritan values of hard work, moral uprightness, and education still remain a part of American culture and morality today.

Full text of Winthrop's sermon